Considerable interest has been generated in recent years in transmitting communication signals in the form of light conveyed by fiberoptics. Many conventional signal modulation techniques are electric and means must be provided for converting such electrical signals to a modulated light beam. Semiconductor laser diodes are quite useful for this purpose since they can be modulated at extremely high rates, however, as the switching speed of signals increases to take advantage of the laser speed, greater difficulties are encountered in coupling the electrical signals to the optical devices.
There is, therefore, a need for a high speed laser control device which will apply modulated signals to a semiconductor laser diode for producing optical signals. Such a device should be rugged and self contained for practical utilization. It should accept signals at frequencies into the microwave range and couple them efficiently without interference to the laser diode. Preferably the device should exhibit a characteristic impedance of fifty ohms to match the impedance of a variety of conventional signal sources. It is desirable that the device be hermetically sealed for enhanced reliability in various environmental conditions. Such a device should be readily controllable, preferably with self-contained diagnostic sensors. It is preferably small and has low power consumption so that heat generation problems are minimized. It is also desirable that such a device be economically manufactured.